The present invention relates to fixtures for supporting workpieces for joining by well known methods of metal fusion such as soldering, brazing and welding.
Techniques of fixturing workpieces are well known in the prior art, but there is no known method that provides a universal fixturing material that is adaptable to support workpieces having a wide variation of goemetric configurations.
The function of the fixture is to securely support two or more workpieces in a desired positonal relationship to one another while effecting their joining. The fixture needs sufficient holding strength to retain the workpieces in accurate relationship without changing dimensionally under the application of heat.
In many industries including the manufacture of dental devices, jewelry and other such delicate assemblies, the fixture must conform to a variety of intricate shapes while effecting a firm grip on the parts. Many prior art fixtures attempt to meet there requirements by providing complicated and costly apparatuses comprising clamps, adjusting screws and other holding and locating members. Once built, these fixtures can serve for retaining only parts having the particular configuration for which they were designed. When differently shaped parts are to be fixtured, another apparatus must be designed and built.
Some prior art devices are shown in U.S. Pat. Nos. 3,110,279 to Brasher; 3,800,408 to Schimmer et al; and 3,897,535 to Lapac et al. The Brasher patent discloses a work positioner comprising a motor driven rotating platform designed to position the workpieces with respect to a welding torch. Schimmer et al describe a method for fixturing semiconductor components utilizing a machined polyimide jig comforming to the semiconductor. The patent to Lepac et al describes a process for fixturing a workpiece in a workholder by introducing a hardenable liquid thermoplastic into the holder after preheating both the workpiece and holder.
None of these devices has the universality of the present invention.